Azo dye.



UNITED STATES PATENT OFFICE.

MYRTIL KAHN, OF ELBERFELD, AND RICHARD KOTHE, OFVOHWINKEL, NEAR ELBERFELD,

GERMANY, ASSIGNORS TO FARBENFABRIKEN VORM. FRIEDR. BAYER & (10., OF ELDER- FELD, GERMANY, A CORPORATION OF GERM ANY.

AZ'O DYE.

Patented Sept. 3, 1907.

Application filed June 5, 1907. Serial No- 377,324-

To all whom it may concern:

Be it known that We, MYRTIL KAHN and RICHARD KOTHE, doctors of philosophy, chemists, citizens of the German Empire, residing at, respectively, Elberfeld and Vohwinkel, near Elberfeld, in the Kingdom of Prussia, Germany, have invented new and useful Improvements in Azo Dyes, of which the following is a fspecification.

f .We have found that a new and valuable azo-dyestuff is obtained by combining the diazo compound of 4- chloro-Z-aminophenol-(S-sulfonic acid with l-naphthol- 5-sulfonic acid.

In carrying out the new process practically-we can proceed as follows, the parts being by weight: 22,4 parts of 4-chloro-2-aminophenol-6-sulionic acid are diazotized in the usual manner by means of hydrochloric acid and 7 parts of sodium nitrite. The diazo compound is then poured into a solution of parts of reddish-violet color. By reduction with stannous chlorid and hydrochloric acid l-chloro-Z-aminophenol- 6-sulfonic acid and 2-amino-1-naphthol-5-sulfonic acid is obtained. The new dyestuff dyes wool from acid baths a bluish-red shade which is changed to a bright fast navy-blue when chromed after dyeing.

Having now described our invention and in what manner the same is to be performed, what we claim as new and desire to secure by Letters Patent is:

The herein-described new azo-dyestutt', which can be obtained by combining diazotized 4-011]ordQ-aminophenol- G-sulfonic acid with l-naphthol-5-sulfonic acid, which dyestuff is, after beingdried and pulverized in the shape of its sodium salt a dark powder soluble in water with a violet color and in concentrated sulfuric acid with a reddish-violet color; yielding upon reduction with stannous chlorid and hydrochloric acid 4-chloro-2-aminophen01-6- sulfonic acid and 2-amino-l-naphthol-S-sulfonic acid; and dyeing wool from acid baths bluish-red shades which are changed to blue when chromed after dyeing, substair tially as hereinbefore described.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

MYRTIL KAIIN. [n RICHARD KO'lHE. [n s] Witnesses O'r'ro Kome, AUG. LANDSIEDEL. 

